Hoping someone can help me. Been having issues with my truck starting. Put a new starter in a week ago and been doing ok. I didn't drive this weekend but went to start it this morning to go to work. Started and ran fine but as soon as I pull the switch out to turn the headlights on they turn on and the truck dies immediately. If I try to start it with the lights on it cranks and cranks but will not turn over. I have power. Battery is only 5 months old. Any ideas? Thanks.

 

did it do the same thing with the old starter ?

 

First things first with electrical problems, clean up your battery terminals, or replace if too bad. You would be surprised how much can be affected by corroded terminals. Next would be to hit the chassis grounds, mainly the engine block to firewall and the battery to fender. You may also want to check the condition of the fuses in both cab and engine bay fuse box, if they have corrosion you need to clean the interior contacts and probably replace the fuses.

Sounds like your lights are pulling more amps than the stock wiring can handle, get a multimeter and test for power at the lights, the light switch, and battery terminal. Do this with just the lights on and nothing else. If worse come to worse you can bypass the stock wiring for the headlights using this write up, it's meant to deter dimming caused by excessive load on the factory wiring by pulling power straight from the battery instead of using the normal supply chain.

 

nope. Did this for the first time.

 

Thanks man. I'll check the grounds. I replaced both terminals months ago and recently checked them so I know they are tight and clean. I'll check fuses as well.

 

So I replaced the headlight switch. Everything worked again like normal......for one trip. After driving for 20 min I started it up and as soon as I turned the headlights on it died again. Any ideas?

 

Check your fuses to ensure that you have the correct amp fuse in each slot, probably just need to check anything light related. Run to an auto parts store and have them test your battery and alternator output just to rule those out. Another thing to try is to unplug both headlights from their sockets and see if that helps, if yes then they are somehow pulling more amps than they should. You can also grab some pieces of wiring and run an extra ground between battery>fender and the engine block>firewall to ensure you are getting a proper ground-this could also be accomplished with jumper cables.

Have you done any upgrades, re-wiring, or alterations to the truck in the past few months? Even if it doesn't seem relevant it would be helpful to know.

 

Thanks for the tip man. No alterations. I've replaced the starter recently. That's about it.